Knife sharpener



April 9, 1968 G R. WOLTER KNIFE SHARPENER 2 Sheets-Sheet 1 Filed Jan. 10, 1966 szu a a: a W d G R. WOLTER KNIFE SHARPENER Aprifi a, 1968 2 Sheets-Sheet 2 Filed Jan. 10, 1966 afd 89% Z Unite States Patent 3,376,671 KNHFE SHARPENER Gilbert R. Welter, Elrnhurst, IiL, assignor to Sunbeam Corporation, Chicago, ill., a corporation of Illinois Filed Jan. 10, 1966, Ser. No. 519,580 7 Claims. (Cl. l-5) This invention relates generally to knife sharpeners and more particularly improvements in combination appliances for opening cans and sharpening knives.

As the market for electric can openers has developed in this country, a substantial demand has built up for can openers which will also perform the knife sharpening function. The power requirements of the can opener are such that the motor provided therein is well suited to power a small abrasive wheel suitable for sharpening knives. Since the knife sharpening portion of the appliance is used rather infrequently as compared to the can opening portion, these combination appliances have been designed to emphasize the can opener portion and make this portion as easy as possible to use. The knife sharpening wheels have generally been positioned to one side or to the rear of the can opener portion of the housing so as to be out of the way during the can opening operation. These sidewardly and rearwardly extending appendages have been unsightly from a design standpoint and expensive to manufacture.

In general, the sidewardly or rearwardly extending knife sharpeners require belts or gearing to couple the abrasive wheel to the motor used for the can opener. The additional housing structure plus the drive connection between the motor and the abrasive wheel result in the knife sharpening portion of the appliance costing almost as much as a separate knife sharpener would cost. Obviously, it would be desirable to add the knife sharpening feature to a can opener at as low a cost as possible. The embodiment of the invention disclosed herein includes a can opener of the type disclosed and claimed in Jepson et al. Patent No. 3,216,108. This can opener is of the type in which the cover is severed from the can be making a circular out along the inside diameter of the end seam. The particular structure of the can opener is, however, immaterial to the application of the present invention.

The invention is applicable to any upright can opener having means for supporting within the normal confines of the housing an abrasive wheel driven by the can opener motor. The invention involves means for slidably supporting a combination knife guide and sharpener cover means on the can opener housing.

It is an object of the present invention to provide an improved knife sharpener which may be combined with a can opener at very little extra cost.

It is another object of the present invention to provide an improved can opener and knife sharpening appliance which utilizes a rotary abrasive wheel having a movable cover member attached to serve as a blade guide.

Further objects and advantages of the present invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of the specification.

For better understanding of the present invention reference may be had to the accompanying drawings in which:

FIG. 1 is a side elevational view of the combined can opener and knife sharpener with the appliance resting in the knife sharpening position;

FIG. 2 is an enlarged fragmentary sectional view taken substantially on line 2-2 of FIG. 1 with portions of the housing cut away to expose the knife sharpening mecha nism;

3,376,671 Patented Apr. 9, 1968 FIG. 3 is an enlarged sectional view taken along line 33 of FIG. 1 assuming FIG. 1 shows the complete structure;

FIG. 4 is a fragmentary sectional view taken on line 44 of FIG. 3 assuming FIG. 3 shows the complete structure;

FIG. 5 is a perspective view of the combined can opener and knife sharpener in the can opening position;

FIG. 6 is an enlarged fragmentary section taken substantially on line 6-6 of FIG. 5; and

FIG. 7 is an enlarged fragmentary front elevational view of the combined can opener and knife sharpener with the cover for the knife sharpener removed for illustrative purposes.

The combined can opener and knife sharpener of the instant invention involves a can opener of the type having a motor positioned in an upright column with a drive connection between the motor and the can cutting means. The abrasive wheel for use in sharpening knives is simply mounted in the interior of the can opener housing with a slidable cover provided to gain access to the edge of the wheel. The sliding cover serves the dual purpose of completing the housing surrounding the wheel in the closed position and of guiding the knife blade into engagement with the wheel when the slide is in the open position.

Referring now to the drawings wherein like reference characters designate corresponding parts throughout the several views, there is shown a power operated can opener generally designated by reference numeral 20. The details of the can opener mechanism are disclosed and claimed in an application Ser. No. 519,616, now Patent No. 3,348,305, for Can Opener filed in the name of Sigmund H. Bielak on the same day as the instant application. In normal operation, the can opener of FIG. 1 is rotated clockwise to an upright position in which it is supported by a base 21 as shown in FIG. 5. The base 21 is formed with recesses in the corners thereof which receive rubber supporting feet 22. The can opener 20 includes a column portion 23 within which an electric motor 29 is mounted and a head portion 24 which encloses the remainder of the can opener mechanism other than the motor. When the can opener 20 is in the upright position for use as a can opener, the column portion 23 extends generally vertically. For the purpose of controlling the can opener mechanism, there is provided an operating handle 25 which is pivotally connected to the head 24. The operating handle 25 serves among other things to move a cutter 26 and a feed wheel 27 into operative position to grip the end seam of a can to be opened.

As rotation of the operating handle 25 moves the cutter and feed wheel 26 and 27 respectively, the free end of handle 25 engages a front switch actuation bar 28. Thus, when the operating handle 25 is pivoted 90 from the position shown in FIGS. 1 and 5, the handle strikes the switch actuating bar 28 energizing the motor and causing the feed wheel 27 to rotate the can in engagement with the cutter 26.

The can opener motor 29 includes an armature shaft 30 which extends lengthwise within the upright column 23. Supported on the lower end of the armature shaft 30 is an abrasive wheel 31. A retaining nut 32 is threadedly received on the lower end of the armature shaft while a helical spring 33 is compressed between a washer 34 secured to the shaft 30 and the abrasive wheel 31. The washer 34 is retained against axial displacement on shaft 30 under the biasing force of spring 33 by a resilient C-shaped ring which is received in an annular groove in shaft 30. The spring provides a friction drive between the motor and the abrasive wheel so that under conditions of overload, the spring coupling may slip to prevent burning out of the motor.

The column portion 23 of the housing is formed with a pair of transversely extending walls 35 and 36 which are disposed on either side of the abrasive wheel 31 as is best shown in FIGS. 1 and 6. The walls 35 and 36 together with the adjoining portions of the housing provide an enclosure for the abrasive wheel which is essentially separate from the motor housing portion except for the snug opening in wall 36 through which shaft 30 extends. Extending transversely of the upright column 23 is a molded V-shaped slot 38. The slot 38 is provided at its central portion with an opening 38a through which the abrasive wheel 31 extends. The adjoining portions at the bottom of slot 38 are closed by walls 38b and 380 as is best shown in FIG. 3.

To protect the abrasive wheel 31 against accidental engagement by the user of the can opener, a cover 40 is formed which is received within the slot 38 as is best seen in FIGS. 1 and 4. The cover 40 is formed with a somewhat pie-shaped contour so that it may slide into seated engagement within the slot 38. To guide the cover 40 for movement with respect to the slot 38, there is provided an elongated guide 40a which is received in a box-like passageway 38d formed in the bottom wall 380 of the slot. In addition to the guide 40a the cover 40 is provided with spaced retaining projections 40b and 400 which lie on both sides of the guide40a and are all in the same plane. As is best seen in FIG. 3, the retaining projection 400 is received in a passageway 38e while projection 40b extends through opening 38a adjacent to wheel 31. The inner ends of the retaining projections 40b and 400 are provided with hook-shaped portions 40d and 402 respectively which engage wall portions of the slot 38 to prevent detachment of the cover 40.

The hook-shaped portions 40d and We are positioned to permit the cover to move outwardly approximately onefourth inch from its seated position within the slot 38. In FIGS. 1-4 of the drawings, the cover is shown in this outermost position in which the abrasive wheel 31 is accessible for use in sharpening knives while FIGS. 5 and 6 show cover 40 in the closed position. As is shown best in FIG. 1, there is defined between the inclined walls of slot 38 and the edges of the cover 40 a pair of converging slots into which a knife blade may be inserted to be sharpened against the wheel 31. The slots serve to guide the knife blade into engagement when either face of the abrasive wheel at the proper angle for sharpening the blade.

Referring to FIG. 3, it is noted that the cover extends across the entire forward face of the abrasive wheel 31 and to the left edge of the upright column 23. On the right edge of the column as viewed in FIG. 3, however, the cover does not extend above the portion of the slot adjacent the bottom wall 38b. The slot 38 is widened in this area to provide clearance for the handle of the knife as is best shown in FIGS. 5 and 7. Thus, the knife blade may be sharpened from the tip of the blade down to a point very close to the handle.

When the can opener 20 is used as a knife sharpener rather than a can opener, it is positioned on a table or counter top as shown in FIG. 1 with the column 23 extending horizontally. Beneath the head portion 24 of the can opener there are provided a pair of rearwardly extending resilient buttons 42 which serve to support the upper end of the can opener 20 when it is positioned in the knife sharpening position. The support feet 22 on the rear edge of the base 21 project rearwardly as well as downwardly and are, therefore, effective to support the lower end of the can opener 20 in the knife sharpening position. After positioning the can opener as shown in FIG. 1, the cover 40 is then moved to the open position and the operator may then sharpen in successive steps the two sides of a knife blade by inserting it in the converging slots formed by the cover 40 with the V-shaped slot 38. When the appliance is used for knife sharpening only, there is no need to utilize the operating handle 25.

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The operator may apply a pivoting force on the switch actuating bar 28 directly to energize the motor and thereby cause rotation of the abrasive wheel 31. When the knife sharpening operation has been completed, the cover 40 may be simply pushed inwardly to a seated position in which it completely closes the opening 38a in the bottom of the slot 38 as is evident from FIGS. 5 and 6. This prevents any accidental engagement of the wheel 31 and also prevents food or other foreign matter from being spilled on the wheel and thereby lessening its effectiveness. The cover 40 is provided with a curved outerwall 40 which has the same contour as the remainder of the column 23 so that when the cover is in the closed position the cover blends with the front portion of the column to present a smooth, appealing contour.

On initial assembly of the cover 40 to the column 23 or upon removal therefrom, the retaining projections 40b and 40a may shaped portions 40d and 40e will clear the wall portions at the base of the slot 38 and will pass through the opening 38a and passageway 38a. This integral plastic means for securing and guiding the cover 40 with respect to the column 23 obviously has considerable cost advantage. In view of the fact that the knifesharpener utilizes an abrasive wheel which is mounted directly on the lower end of the armature shaft 30, the entire knife sharpening portion of the appliance 20 adds very little to the cost of the unit. The guiding portions comprising the slot 38 on the column 23 are obtained at little or no cost when the molded plastic housing is fabricated. Similarly, the internal walls 34 and 35 which separate the sharpening area from the remainder of the housingare obtained for only the cost of the material involved which is obviously very small. The assembly means for the abrasive wheel 31 are also relatively inexpensive items. Accordingly, the knife sharpener of the instant invention is very inexpensive and provides a knife sharpener which is well integrated with the can opener so as to be easy to use when necessary but at the same time it does not obstruct use of the can opener in any way or detract from the styling of-the unit.

While there has been illustrated and described a single preferred embodiment of the invention, it will be readily understood by those skilled in the art that numerous changes and modifications can be made without departing from the present invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A combination appliance having can opening and knife sharpening means comprising a housing enclosing a motor drivingly connected to can opening means, said motor having an armature shaft supporting at one end thereof an abrasive wheel within said housing, a V-shaped knife blade guiding slot formed in one wall of said housing, said abrasive wheel extending into said slot through an opening in the bottom thereof, a combined blade guide and cover mounted on said housing for slidable movement in said slot, said cover movable between a first position closing said slot and a second position in which the walls of said cover and the converging walls of said slot define a pair of converging knife blade guiding slots the planes of which intersect opposite faces of said wheel.

2. The combination appliance of claim 1 wherein said cover comprises a one-piece plastic part having molded guiding and retaining projections formed thereon, said projections being received in passageways formed on said housing to guide said cover for said slidable movement.

'3. The combination appliance of claim 1 wherein said housing includes a pair of transverse walls extending completely across said housing on either side of said abrasive wheel to provide a chamber separate from the remainder of the interior of said housing.

4. The combination appliance of claim 2 wherein said projections comprise a first relatively rigid elongatedmember extending rearwardly and being received in an be deflected sufficiently so that the hookelongated passageway formed in said housing, second and third projections extending parallel said first elongated projection and being flexible in a plane common to said projections, said second and third projections having retaining means on their free ends which interlock with the interior of said housing to retain said cover on said housing.

5. A combination can opener and knife sharpening appliance comprising a generally upright housing supporting a can opening means in the upper portion thereof, a motor in said housing drivingly connected to said can opening means and driving a vertically extending shaft, an abrasive wheel supported on said shaft within said housing, said housing being formed with a V-shaped slot extending horizontally thereon below said can opening means, said wheel extending into the bottom of said slot through an opening in said housing, a combined cover and blade guide mounted for limited horizontal movement in said slot, said combined cover and guide being movable between a first osition in which it completely closes said slot and a second position in which it defines with the walls of said slot a pair of converging blade receiving openings which terminate at the opposite faces of said wheel.

6. The combination can opener and knife sharpener of claim 5 wherein support means are provided on said housing to support said housing in horizontally extending position in which said V-shaped slot is facing upwardly and said Wheel supporting shaft extends horizontally.

7. The combination can opening and knife sharpening appliance of claim 5 including a operating lever pivotally mounted on said housing for energizing said motor and controlling said can opening means, said lever being movable into engagement with motor switch controlling means positioned exteriorly of said housing to energize said motor, said switch con-trolling means being positioned for manual operation when said appliance is used for sharpening knives.

References Cited UNITED STATES PATENTS 2,897,637 8/1959 Bodle 51-128 3,075,322 1/1963 Uthoif 51-128 3,146,555 9/1964 'Posener 51-128 2,522,942 9/1950 Gillen 51-128 JAMES L. I ONES, IR., Primary Examiner. 

1. A COMBINATION APPLIANCE HAVING CAN OPENING AND KNIFE SHARPENING MEANS COMPRISING A HOUSING ENCLOSING A MOTOR DRIVINGLY CONNECTED TO CAN OPENING MEANS, SAID MOTOR HAVING AN ARMATURE SHAFT SUPPORTING AT ONE END THEREOF AN ABRASIVE WHEEL WITHIN SAID HOUSING, A V-SHAPED KNIFE BLADE GUIDING SLOT FORMED IN ONE WALL OF SAID HOUSING, SAID ABRASIVE WHEEL EXTENDING INTO SAID SLOT THROUGH AN OPENING IN THE BOTTOM THEREOF, A COMBINED BLADE GUIDE AND COVER MOUNTED ON SAID HOUSING FOR SLIDABLE MOVEMENT IN SAID SLOT, SAID COVER MOVABLE BETWEEN A FIRST POSITION CLOSING SAID SLOT AND A SECOND POSITION IN WHICH THE WALLS OF SAID COVER AND THE CONVERGING WALLS OF SAID SLOT DEFINE A PAIR OF CONVERGING KNIFE BLADE GUIDING SLOTS THE PLANES OF WHICH INTERSECT OPPOSITE FACES OF SAID WHEEL. 